Motor-controller.



G. R. RADLEY.

MOTOR CONTROLLER.

APPLICATION mum JUNE 3'. 1912.

1,1 10,821; Patented Sept. 15, 1914.

22 25 CHI/766 OFF - RUN ii? !L!!! UNITED STATES PATENT OFFICE.

GUY R. RADLEY, OF MILWAUKEE; WISCONSIN, ASSIGNOR TO THE CUTLER-HAMlliE-R MFG. CO., OF MILWAUKEE, WISCONSIN, A CORPORATION OF WISCONSIN.

MOTOR-CONTROLLER.

Specification of Letters Patent. Application filed June 3. 1912. .Serial No. 701 -1.

Patented Sept. 15, 1914.

1'0 all ii /16 nit may concern: A Be it known that I, GUY R. Banner, :1 citizen of the United States, residing at Mil- .waukee, in the county 'of Milwaukee and State of v\Visconsin, have invented new and My invention relates to imprm lnentsin,

' motor oontrollersand more particularly to 1 controllers for" electric vehicles, although or both.

certain features thereof may be a di'antageously employedinlother relations.

.One of the ohject sjo'fthe n' ntion s to troll'er foiflcornmutatingthe windings of. the,

controlled inotor, .or the sup p l Ibatteries,

A further ohjectis to proridenieans for automatically regulating the supply of power. 'to insure safe and econonngil 'conr 1 A still furtherfobject is to' provide a safe tairrsteps" of wntr'ol may be effected liy :1

Switch or switches operable hyone. or -ho th brake pedals.

)ther ohjeets and advantages will hereina fter appean For the purpose of fully and clearly disclosing the nature and advantages of.my invention 1 shall describe the controller dingrammatically illustrated in the aeeomp-nrving drawing. It should of course be understood that. the controller. illustrated is susceptihle of various modifications.

The controller illustrated is design d partienlarlv for electric automobile servire.

The driving motor 1 has an armature and series field windings l and 1?. .\s e. ill later he set forth, the field windings are adapted to he connected in either Series or parallel relation to vary the speed of the. motor. Of course other types of motors might be employed. and-the fieldregulation thereof ohtaincd by other means than series;- parallel field connections. Storage hatteries 2 and are pro ided for supplying power to the nit-tor. The liatterh I are-adapted to he connected in either series or parallel relation to vary the potential and current eon (litions in the motor cireuit.-

The controller'lncludes an elcctroresponbl cone: hatteries when the batteries ai responsive armature )GVCl'E-lllg switch (3. an

elta-trm'esponsive series-parallel switch 7 for the'lield windings and an electrores mnsive seriesp: "allel switch 3 for the hattziries. 'lhese switches are. all controlled iiy a murder switch MS which in the drawing is developed as a drum controller hut which in practice may assume an desired form. The controller also includes a battery relay switch BR and a field relay switch FR. 'llhe hattery relay switch has an operating windingconneetedin series 'ith oneof the e anaemia parallel and functions to prevent the changmg of the batteries to series relation, while -oertainfelectrieal.conditions prevaiL- it is renderedinoperative as soon as the batteries are connected in series. The operating -winding, of the, field relay is permanently connected in seriesin the motor circuit and responds under pertain conditions to .prevent the. weakening oi" the motor field by paralleling the fieldwindings and to change. the lield windings hack to series relation if previously connected in parallel. The provision of these relays and the particular arrangement thereof constitute an importantfeature of the (ontroller, aswill later he apparent.

In electric auton'iohiles it is very desir able. and often imperative. to be able to control the motor h v the brake l(\'el$. l have accordingly asmeia-ted with the controller a switch 10 for connection to the service or non-locking.hralce lever IL and a switch 12 fo connection to the. en'lergeney or locking lt-rake lever 13. Th" switch connected to the enri'gi-uer lu'alt': lever disconnects the motor from (-irerii iiilil'niiliiitllf upon application of the enwz-gency hralce and the controller is so designed that when the motor has heen thus disc nnected it can on y he again conueetrd l\ v operation of the master switch or hy thesen iee lrrake switch in a maunerhereinater set fir'th. The service lirah'e switch on theother hand is adapted to disconnect the n'totor from circuit when the hrake is applied and to again connect the motor in circuit when the brake is released. This service brake switch is provided with stationary contacts l4. l5 and 16, which contacts it engages in difierent positions of the normally closed switch 18 in circuit with the. operating windingof the main switch. This switch is adapted to be opened upon the opening of. the vehicle door to disconnect motor from circuit when in operation and to prevent the motor from being started until the door is closed.

As will later be seen, when the master switch is in off position the batteries are connected in series and accordingly are in a proper relation to be charged, from a suitable charging circuit 19. The batteries are adapted to be connected to the charging circuit by a switch 20. This switch has three positions, namely, a running position in which it engages a contact 21 connecting the batteries to the motor circuit, a charging position in which it engages a contact 22 to connect the batteries to one side of the charging circuit and an off position in whichit engages adead contact: 23. Theopposite side of the charging-circuit is'per'manently connected to one side of the batteries.

Switches 6, 7" and 8 are double-pole double-throw switches" each having a set of up contacts a and I), a set of down contacts 0 and d, and insulated movable contacts 0 and f. When these switches are deiinergizcd their movable contacts engage the down contacts. The master switch is provided with a set of contact fingers. 24, 25, 26 and 27 adapted to be moved into engagement with either one or two sets. of contact segments disposed on opposite sides thereof. An additional finger 28 is provided to continually engage a segment 28*. The fingers are all electrically connected. The segments on the right of the fingers are designated :'24", 24". 2:1,

gcrs are designated as 24", 2-l,25", in and 27.

I shall now described the operation of the controller: \Vith the various switches of the controller in the positions illnstrah d. the motor is disconma-tcd from circuit. it may be started by movement of the master controller in either direction according to the direction of operation desired. If forward operation is desired, the controller is. moved to the right, causing finger 35 to first engage segment This completes a circuit from the positive terminal of battery 2 by conductor to segment 28 and finger 28 to finger 25 and segment 25 by conductor 31 to a. segment 25 by conductors 3:2 and 33 through .the batteries 'in"parallel.

Qt? and 36" and those on the left of said finthe operating winding of battery switch 8 by conductors 34 and 35 through switch 20 by conductor 36 to the negative side of battery 2. Switch 8 thereupon responds causing-its movable contacts 0 and f to engage the up contacts a and. respectively. Themovable contacts a and f are connected by flexible conductors to opposite terminals of batteries 2 and 3 and the engagement of contacts e and f with up contacts a and 1) places Continued movementof the master controller to the full first position causes finger 24 to engage fin gcr 24 which con'iplctcs a circuit from the {positive terminal of battery 2 to the master switch fingers as already traced, thence to segment 24 by conductors 37 and 38 through service brake switch 10 and emergency brake switch 12 by conductors 39 and 40 through the doorswitch 18 and thence through the operating winding of the main switch by conductors 41 and 4.2 to conductor 35, which as already described leads back to the negative terminal of battery 2. Thcreupon main switch 4 closes and connects the motor to the batteries. With the batteryswitch in up position the positive terminals of the batteries are connected at the point marked at. From this point the motor circuit extends by conductor 43 through the operating-winding of the field relay switch FR by conductor 44' through contacts 0 and c of the reversing switch by conductors 45 and 46 through the motor armature in a left hand direction by conductors47 and 48 through 00 the reversing contacts 1 11nd d, by conductor 49, through field winding F, contacts 0 and c of the field switch by conductor 50 through contacts f and (l of the field. switch, thence through field winding F by conductor-51 105 through the resistance by conductor 52 through main switch 4 by conductor 53 through switch '20 lothcpoint marked us. Here the circuit divides, one branch extending by conductor 36 to the negative terminal 110 of battery 2 and the other branch extending by conductor 54 through the winding of battery relay BR by conductor through the contacts I) and f of the battery switch 8 to the negative terminal of battery 3. The 115 motor is thus started, but with the resistance ll included in the circuit therewith. \Vhen the motor circuit is thus closed there is likely to be a heavy surge of current in the motor circuit and if this surge is'sulliciently 120 heavy the relays BR and F 1 will respond. These relays of course may beadjustcd to respond at any predetermined current value. The relay BR upon responding establishes a maintaining circuit for the battery switch 126 in parallel to the master switch. This maintaining circuit may be traced from the positive terminal of the battery Zby conductor through the battery relay switch by conductor 61 to conductor 33.. Thus so 1 predetermined value when the third position operation of the .field switch. \Vhen the 'maintaining circuit prevents the dropping would prevent the changing. of the field from long as this relay remains up the batteries will be maintained in parallel relation. The relayswitch FR, as will later be more specifically set forth, is in series with the operating winding of the field switch and accordingly if it responds it will prevent the controller is moved to the second forward position a circuit will be closed from seg-- ment 24 by conductor 62 to segment 24 by conductors 63 and 64 through an auxiliary switch 65 closedupon closure of the main switch, by conductor 66 through the operating windingof accelerating switch 5 by conductor 67 to ionductor t1 and thence toncgative side of battery 2, as alr'eady traced. Switch 5 thereupon responds 'short-circuiting the resistance R and accordingly accelerating the motor. \Vheii*-the full second position is reached circuit is broken between finger 24 and segment 24, but this circuit is not broken until after finger 24 engages segment 24", whereupon a maintaining circuit is established for the main switch 4. This out of switch 4 upon disengagement of the finger 24 from-the segment 2d. The main taining circuit extends from segment 24" tosegment 24 by conductors 63 and 68 through, a maintaining andintcr cking resistance 69 to conductor 38. Should the main switch 4 from any cause become deenergized after the establishment of these connections it could not again respond until the resistance 69 was short circuitcd. This resistance can only be short eircuited by returning the master controller to thefirst position or by moving the service brake switch 10 into engagement with contact 15. This, as will be later apparent insures against the motor being started at any but the proper speed. W hen the master controller has moved to the third position circuit is closed from finger 26 to segment 26 by conductor 70 to segment 2G by conductor 71 through the field relay switch, conductor 72 through the operatin winding of the fieldswitch 7 by conductor 43 to conductor 42 and thencecto the negati e side of the batteries. The field switch thereupon responds changing the relation of the field windings F and If from series to parallel. This further accelerates the motor. Should the current in the motor circuit exceed a is reached the relay FR would be in up position thereby preventing the closure of the energizing circuit of the field switch, This series to parallel relation until normal coirditions were restored. Further should the current in the motor circuit rise above said predetermined degree after the fie d windings were w-nnected in parallel glue to an increased load. as for esaniple would resul from ascending a steep. grade, the relay would respond thereby dec-nergizing the field switch and re'e'stablishing the series connections between the field windings. This would result in building up the field strength and consequently increasing the torque of the motor and reducing the power consumption. Thus the relay FR insures economy of power and full field strength under heavy load conditions. The building up of the field'strength and reduction of power of course tends to protect the motor and other parts likely to be injured by an excess of current. lVhen the master switch is moved to the fourth position contact is first broken bet-ween finger 26 and segment- QU thereby denergizing the field switch which results in reiistablishing the series connections between the field windings. \Vhcn the full fourth position is reached the finger 25 is disengaged from segment 25* thereby deenergizing the battery switch, which upon dropping relistablisbes the series connection bet-ween the batteries. This further accelerates the motor. The operation of the battery switch, however, is subject to the con trol of the relay BR as before explained, for should the current in the motor circuit exteed a predetermined value at the time the master controller was moved to the fourth position the relay BR would be energized completing. the maintaining circuit for the battery switch 8 as before described. Under such conditions the movement of the controller to the fourth position would have no elfect upon the battery connections, which would remain the sameuntil the motor current had dropped to the proper alue to release the relay BR. Thus the relay BR will maintain the parallel connections between the batteries so long as the motor current exceeds a predetermined value. thereby coiipcrating, with the relay Fll to insure economy of power and safe control. \Vhen, however, the relay BR once drops after the master controller has reached the fourth position it is rendered inoperative until the master controller is returned to the third position or the service brake switch is operated in the r hereinafter scl forth. ovcmeut of the riff-stro l r to lll! fifth p sition again cuergazcs the field switch, subject how ver to the operation of the field relay, to reestablish parallel connections between the field windings to further incrrasc. the speed of the motor. Thisgivcs the maximum speed obtainable by the master controller. Should a still higher speed be desired the switch 17 is operated to connect a portion of the resistanceR in parallel with the field windiufls. This results in still further weakening the motor field and accordingly increas ing the speed of the motor. To reverse the motor to run the machine in the opposite direction it is onl: necea ary to reverse the operation of the contact fingers 9.4 moving will have passed out of engagement with switch to drop out and disconnect the motor them into engagement with the left hand set of segments. Upon initial movement in this direction circuit is first closed through" the operating winding of the batteryswitchto cause said switch to connect the batteries in parallel and at the same time'circuit is closed through the operating winding of the armature reversing switch. This circuit may be traced to finger 27 to segment 27 by conductor 75 through the .o crating winding of switch 0 by conductor) to conductor The switch (3 thereupon responds connecting the positive terminals of the batteries through reversing switch contacts a, a to the left hand terminal of the motor armature and connecting the right handterminal of the motor armature through reversing contacts b, f to the field coils. This causes current to flow through to the motor armature in a right hand direction and accordingly reverses the operation thereof. In the full first reverse position of the master con,- troller, circuit is clo'sedthroughtlie operating winding of the main switch 4 which thereupon responds completing the: motor circuit. In the second osition the switch 5 is energized to short circuit the resistance R and in the-third position the switch 7 is energized, subject however to the' control of i the relay FR to parallel the field windings F and F. Of course higher speeds might be provided for on reverse if desired, but ordinarily the paralleling of the field windings with batteries in parallel gives a'speed sufliciently high for allpr'actical purposes.

I 'Will now describe theoperation and function of the brake switches 10 and 12: First, referring to the service brakgiswitch, the same normally stands in .engagement with contact 14 \Vhen however the service brake lever is'operated to apply,its mechanical brake, it first moves the SYitClTalOjIlLQl engagement with coutacts'15 and lfi i'vhile taking up the slack in th brake rigging and before the brake shoes act itally touch and begin retarding the car speed, the lever 10 switch segment 24 to 24 by conductors 63 and 68 through the switches 10 and 12 by conductors 39 and 40 through the winding of switch-4 as already traced. At the same time circuit is closed from conductor (38 to contact 15-across switch 10 to contact 16 and thence by conductor 77 through the operating winding of the battery switch 8 by conductor 35 to the negative side of the batteries The switch 8 thereupon responds connecting the batteries in parallel, as previously described. After. the motor is thus started the switch 5 automatically responds .to cut out the resistanceR from circuit and after the switch 5 responds then the field switch will automatically ,respond subject tothe control of the relay FRtoparallel the field windings F and F. Then if the service brake switch 10 is permitted to move out of engagement with contacts 15 and 16 and into engagement with contact 14 the-battery switch will under the proper conditions drop out to reestablish series connections between the batteries. It will be observed, however, that in starting the motor by the service brake switch the battery relay is again connected in circuit and accordingly will prevent the reestablishment' of series connections between the batteries so long as abnormal chi rent conditions prevail in the motor circuit. Thus the same protection against injury'and waste of power is insured upon switch as upon starting the motor by the master controller.

of the emergency brake. When it opens it breaks the maintaining circuitof the main from circuit as above descrihctt' This switch while effective to open the motor circuit in an emergency is ineffective to rcclose the closure of this switch is prevented by the interlocking resistance 69, which when the service .brake switch 10 stands in normal position is connected in series with the operating windings of the main switch 4.. This s resistance is of such a design as to so reduce from circuit. Switch 4 in dropping-out dethe flow of current through the operating contact 15. This interrupts the maintaining circuit of the main switch -t crihslng said energizes switch 5 thereby re-inscrting the winding of switch 4 as to preventresponse resistance R in circuit. Thus this operation of said winding. After opening the motor of the service brake lever disconnects the I circuit by the emergency brake switch the motor from circuit and enables the car to be motor circuit can only be reclosed by the checked or even stopped without operation i master switch or by the service brake switch. of the master controller. Assuming now that l A further feature of the controller con the master controller is left in the fourth i sists in connecting the contacts 6 and f of the forward position after the motor has beeni field controlling switch 7 through a restopped the motor may be restarted by the g sistancc R (shown in dotted lines). This service brake lever. Upon release of this resistance performs a double function. As lever the switch 10 is moved into engagement i will be readily apparent, it is short circuited with contacts 15 and 16. This results in re- 1 by the field switch when in position to conestablishing the energizing circuit of main 1 switch 4, which may be traced from master lels the field windings when said switch restarting the motor by the service brake The emergency brake switch 12 is nor malty closed and is opened upon application.

switch 4 thereby disconnecting themotor same. Rcclosure of the motor circuit by'remeet the field windings in series and paralsponds to connect said windings in parallel. This obviously augments the increase in speed obtained by the operation of the field switch, for the inclusion of the resistance in parallel to the field windings further decreases the field strength. Thus by varying the value of the resistance the degree of acceleration obtained by operation of the field switch may be regulated as desired. It enables the same degree of speed variation being obtained by the field switch as by the battery switch. Secondly, the resistance R maintains circuit between contacts e and f of the field switch as it moves from series to parallel position. This preserves the continuity of the motor circuit during the change of the field connections and eliminates areingat the contacts of. the field switch. It'will thus be seen that while this resistance may not be essential 'it is highly desirable.

Having thus described my invention. what I claim as new and desire to secure bYLetters Patent is 1. In a'motor controller, in combination, batteries for supplying power, means for commutatin said batteries from parallel to series inclu ing'governing means insuring against establishment of series connections except under normal power conditions and a-controller adapted to be set to cause operation of said commutating means automatically to establish series connections for said batteries upon restoration of normal power conditio'ns following an abnormal power variation.

2. In a motor controller, in combination, batteries for supplying power, electro-re sponsive means for connecting said batteries in either series or parallel relation, electroresponsive means responsiveto prevent o eration of said former means to establish series connections, and a master controller adapted to be set to cause automatic operation of said first-mentioned means when said second-mentioned means becomes ineffective.

3. In a motor controller, in combination,

storage batteries ,for supplying povvjcr, electfo-rcsponsive means adapted when deiinen gizcd to connect said batreries in series and upon response to connect the same in par allel, and automatic means tending to main tain said electro-rcspp nsive means energized so long as certain electrical conditirms prevail. I

4. In motor controller, in wmbination, storage batteries focsupplying power, elem tro-responsive means adapted when dei ncn gized to connect saidbattcriesin series and upon response to connect said batteries in parallel, and a controller for said means.

In a motor controller, inv combination, storage batteries for supplying p wer. means for connecting said batteries in either series or parallel, and an-electro-rcspoiisive governing device for said means included in circuit upon the. establishment of parallel connections and disconnected from circuit upon the establishment of series connections.

6. In a motor controller, in combination, storage batteries for supplying power, electro-responsive means responsive to change the connections of said batteries from series to parallel, and means responsive to certain electrical conditions to prolongenergization of said former means to maintain parallel connections for said batteries, said latter means being inoperative except while said batteries are connected in parallel.

7. In a motor controller, in combination, batteries for supplying power, electro-responsive means responsive to change the connections ofsaid batteriesfrom series to parallel, and a current.relayarssponsive to main: tain' said'means energiie'd while predetermined electrical conditions prevail, said' re lay being disconnected from circuit upon interruption of the parallel connections of said batteries. e

8. In a motor controller, in combination, batteries for supplying power to the motor, means for connecting said batteries in either series or parallel, field-weakening means for the motor, means automaticall responsive to insure against operation 0. said latter means while predetermined electrical conditions prevail, and means automatically responsive to insure against operation of said first-mentioned means to-connect'said bat teries in series while predetermined electrical conditions prevail, said last mentioned means being ell'ective only while parallel battery connectionsare established. r

9. In combination, a motor, batteries for supplying power thereto, electro-responsive means for connecting said batteries in series or parallel, elcctro-rcsponsive means for controlling the field strength of said motor, and elcctro-responsive relays for separately con trolling the aforesaid means to prevent the establishment of series battery connections and field-weakening cf the motor while certain electrical conditions prevail in the motor circuit, the operating winding of said battery relay being connected in series with but one of said batteries, and the winding of the other relay being connected in series with both of said batteries.

10. In combination, a motor, batteries for supplying power thereto, electro-responsive means for connecting said batteries in series or parallel, electro-responsive means for controlling the field strcngth of said motor, and electro-responsive relays for separately controlling the aforesaid means-to prevent the establishment of series battery connections and field-weakening of the motor while certam electrical conditions prevail in the motor circuit, the operating winding of said battery relay being connected in series with but one of said batteries, and excluded from circuit by series connection of said batteries.

11. In a motor controller, in combination, batteries for supplying power, means for commutating said batteries from parallel to series including governing means-insuring against commutation of the batteries from parallel to series except under normal power conditions, means for weakening the field of the motor including governing means insuring against operation thereof except under normal power conditions and a master controller for said batteryv cominutating means and said field weakening means adapted to be setyto cause either or both of the same to operate automatically upon restoration of normal power conditions following an abnormal power variation.

12. In a motor controller, in combination, batteries for supplying power, electro-responsiremeans for connecting said batteries in either series or parallel, electro-responsive means effective while abnormal electrical conditions prevail to preventopera- 'tion of said former means to establish series connections, electro-responsive fieldweakening means for the motor, electroresponsive means for preventing operation ofsaid field-weakening fneans while abnormal electrical conditions prevail and a master controller for said battery-controlling means and said field-controlling means adapted to be set to cause automatic operation thereof ppon restoration of normal conditions.

13. In a motor controller, in combination, series and parallel connections for the motor field windings, and electroresponsive means adapted when decnergized to complete said series connections and open said parallel connections and when energized to complete said parallel connections.

14. In a motor controller, in combination,'

series and parallel connections or the motor field windings, a resistance included in said series connections, means "adapted in one position to open said parallel connec tions and short-circuit said resistance and when in another position to close said parallel connections and interrupt the short circuit around said resistance.

15. In a motor controller, in combination,

series and parallel connections for the motor field windings, a resistance included in said series connections, and electro-responsive means adapted when decnergized to shortcircuit said resistance and open said parallel connections and when energized to com plete said parallel connections and interrupt the short-circuit around said resistance.

16. The combination with a plurality of electrical devices, of means for connecting the same in either series or .parallel comprising a switch having two pairs of contacts adapted to engage to establish parallel connections and a contact device to bridge one of said pairs of contacts to establish series connections.

17. The combination with a plurality of electrical devices, of. means for establishing either series or parallel connections therefor without interrupting the continuity of the circuit thereof consisting of two contacts, a resistance connecting the same, and co Eperat-ing contacts therefor comprising two electrically independent contacts and an electrical bridge.

18. In a controller formotor operated vehicles, in combination, means including a device to be actuated. by the'operator for establishing running connections, a door switch associated with said means to efiect" parallel connections for said batteries and electro -responsive means adapted, whende energized, to complete said series connections and interrupt said parallel connections and upon response to. oomplete'said' parallel connections and;ifiterrupt said series connections.

'20. In a controller for electric vehicles, in combination, electro-responsive means for controlling the power supply, a hand controllcr for said electro s-responsive means and a switch adapted to be connected to a brake operating mechanism of the vehicle for controlling said electro-resp'onsivc means to interruptthe power supplyinde pendently of'said hand controller and to re stablish the power supply, but onlywhen said hand controller is in'a-running position and only.- :lfter'a definite action of said electro-responsive means.

2].. in a controller for electric vehicles, in combination, batteries for supplying power, electio responsive means for connccting riesor parallel, a hand controller for said clcctro-rcspqnsire means, and means associated with (i brake mechanism of the vehicle for controlling said.clcctrowesponsive means to disconnect said lmttcrics fro circuit independently of said master controller and when said master'controller is in batteries-series position to also cause said electro-responsive means to again connect said batteries in circuit and in series but only after parallel connection thereof.

in a controller for electric vehicles, in combination, a driving motor, batteries for supplying power, haiid-operated means for starting and accelerating said motor by commutation ofsaid batteries from -parallel to said batteries in circuit in either se- 1,1 IO,B21

- series and foot-operated means for stopping said motor independently of said handoperated means and for restarting and accelerating but only when said hand-operated means is in a running position, and only by' first paralleling said batteries.

The combination with a motor operatcd vehicle having a nonlocl ing braking mechanism and a locking brake mechanism, of a master controller for said vehicle, and means associated with said brake mechanism for stopping the vehicle independently of said master controller, the means associated with said non-locking mechanism being also adapted to restart but only when said master switch is in-a running position.

24. The combination with a vehicle having a locking brake mechanism of a hand operated power controller for said vehicle, means associated with said brake mechanism or interrupting the power supply of said vehicle, and means controlled by said handoperated controller to render said former means ineffective to reestablish the power pv y- -25. In a controller for electric vehicles, in combination, an electro-responsive startin and accelerating ,means, a master 'switc controllingbsaid nieans, a switch connected to a brake mechani simof the vehicle to con trcl said means to trruptthe power supply independently of 'said master switch and to restart but only when said master switch is in a'iunning osition, and only under the power conditions first established by said master switch.

26. In a controller for electric vehicles, in

'combination, electf'o-responsix e starting and accelerating means, a master switch, a switch connected 'with a brake mechanism of the vehicle for controlling said means, said latter switch being operable to stop independently of said master switch and also when said master switch is in a running position to restore the vehicle to the speedat which -motor independently of said hand switch and to restart but only when said hand switch is in a running position and the batteries in parallel, and means for preventing series connection of said batteries by either of said switches while abnormal conditions prevail.

29. I a controller for electric motor operated 'ehicles, in combination, electro-responm've starting and accelerating means, a '7 5 master switch for said means, a switch associated with a brake mechanism of the vehicle v for controlling said means to stop and start while said master switch is in a running position and automatic governin means for said master switch is set but only after progressn'e establishment of circuits previously established by said master switch.

27. In a controller for electric vehicles, in 5 combination, electro-responsive starting and accelerating means, a master switch therefor, a switch associated with a brake mechanism of the vehicle for controlling said means to stop and also restart when said said electro-responsive means e 'ective dur- -ing the control of the latter either by said master switch or by said brake switch.

30. In a controller for electric motor operated vehicles, in combination, electro-responsive' starting means, a master switch operable to energize said means, means preventing the response of said starting means in certain running positions of said inaster' Y switch, and a switch associated with a brake 9O mechanism of the vehicle to deenergize said starting means and to control said secondmentioned means to again energize said starting means Without further operation of said master switch.

31. In combination, a motor having a pluralityof field windings, means for establishing either series or parallel connections for the motor field windings, and a resist: ance associated with said means to preserve the continuity of the motor circuit during commutation of the motor field windings and to be connected in parallel to the motor field winding upon parallel connection ofmaster switch is in a running position, and

means insuring against starting by either witnesses.

GUY R. HADLEY.

\Vitnesses:

FRANK H. HUBBARD, IVALTER E. SAaoEN'r. 

